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gh-jezweb-claude-skills-ski…/templates/queues-consumer-explicit-ack.ts
2025-11-30 08:24:26 +08:00

158 lines
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TypeScript

/**
* Queue Consumer with Explicit Acknowledgement
*
* Use when: Operations are non-idempotent (NOT safe to retry)
* Examples: Database writes, payment processing, API calls with side effects
*
* How it works:
* - Call message.ack() after successful processing
* - Only acknowledged messages are removed from queue
* - Failed messages can retry independently
*
* Setup:
* 1. Create queue: npx wrangler queues create my-queue
* 2. Create DLQ: npx wrangler queues create my-dlq
* 3. Add consumer binding with DLQ (see wrangler-queues-config.jsonc)
* 4. Deploy: npm run deploy
*/
type Env = {
DB: D1Database;
API_KEY: string;
};
export default {
async queue(
batch: MessageBatch,
env: Env,
ctx: ExecutionContext
): Promise<void> {
console.log(`Processing batch of ${batch.messages.length} messages`);
// Process each message individually
for (const message of batch.messages) {
try {
// Non-idempotent operation
await processNonIdempotent(message.body, env);
// CRITICAL: Explicitly acknowledge success
message.ack();
console.log(`✅ Message ${message.id} processed successfully`);
} catch (error) {
console.error(`❌ Failed to process message ${message.id}:`, error);
// Don't call ack() - message will retry
// After max_retries, sent to DLQ (if configured)
}
}
// Note: We DON'T throw an error here
// Only unacknowledged messages will retry
},
};
/**
* Process message with non-idempotent operations
*/
async function processNonIdempotent(body: any, env: Env) {
switch (body.type) {
case 'create-order':
await createOrder(body, env);
break;
case 'charge-payment':
await chargePayment(body, env);
break;
case 'update-inventory':
await updateInventory(body, env);
break;
default:
throw new Error(`Unknown message type: ${body.type}`);
}
}
/**
* Example: Create database record (non-idempotent)
*/
async function createOrder(data: any, env: Env) {
// Insert into database (can't be retried safely)
const result = await env.DB.prepare(`
INSERT INTO orders (id, user_id, total, status, created_at)
VALUES (?, ?, ?, ?, ?)
`)
.bind(
data.orderId,
data.userId,
data.total,
'pending',
new Date().toISOString()
)
.run();
if (!result.success) {
throw new Error(`Failed to create order: ${data.orderId}`);
}
console.log(`Order created: ${data.orderId}`);
}
/**
* Example: Charge payment (non-idempotent)
*/
async function chargePayment(data: any, env: Env) {
// Call payment API (can't be retried safely without deduplication)
const response = await fetch('https://api.stripe.com/v1/charges', {
method: 'POST',
headers: {
'Authorization': `Bearer ${env.API_KEY}`,
'Content-Type': 'application/x-www-form-urlencoded',
},
body: new URLSearchParams({
amount: String(data.amount),
currency: data.currency,
source: data.token,
description: data.description,
}),
});
if (!response.ok) {
const error = await response.text();
throw new Error(`Payment failed: ${error}`);
}
const charge = await response.json();
console.log(`Payment charged: ${charge.id}`);
// Update database with charge ID
await env.DB.prepare(`
UPDATE orders SET payment_id = ?, status = 'paid' WHERE id = ?
`)
.bind(charge.id, data.orderId)
.run();
}
/**
* Example: Update inventory (non-idempotent)
*/
async function updateInventory(data: any, env: Env) {
for (const item of data.items) {
// Decrement inventory count
const result = await env.DB.prepare(`
UPDATE inventory
SET quantity = quantity - ?
WHERE sku = ? AND quantity >= ?
`)
.bind(item.quantity, item.sku, item.quantity)
.run();
if (result.changes === 0) {
throw new Error(`Insufficient inventory for SKU: ${item.sku}`);
}
console.log(`Inventory updated: ${item.sku} (-${item.quantity})`);
}
}